Greenpeace activists, Canadian Terry Christenson among them, were first offered hot soup, then showered with blasts of cold water and pieces of metal after they stormed a floating Russia oil platform and erected climbing tents on the side of the rig on Friday to protest drilling in the Arctic.

The six activists, who include Greenpeace executive director Kumi Naidoo, spent several hours hanging off the side of the Prirazlomnaya platform in the Pechora Sea attached to the rig's mooring lines. They had prepared for a long occupation by bringing up supplies, including the tents, but left after rig workers threw pieces of metal at them.

"Not just hosed water, but now metal being thrown by Gazprom crew at our activists," he said in a tweet, referring to the workers of a subsidiary of Russian energy company Gazprom that owns and operates the rig. "We're coming down."

In response to a question from the Los Angeles Times sent to him later through Twitter, Naidoo said the activists had indeed left the platform. Gazprom officials were not immediately available for comment on whether workers had used hoses on and threw metal objects at the activists.

The group, led by Greenpeace chief Kumi Naidoo of South Africa, includes two activists from Germany, and one each from the United States and Finland. Christenson is from Parry Sound, Ont., and has been with the group for four years.

Initially, two helicopters arrived at the platform, but left without disturbing the protesters. The activists managed to put a banner on the rig saying "Don't kill the Arctic."

Rig employees have been spraying the activists with water (Denis Sinyakov/Greenpeace/Associated Press)

"We're here peacefully and we will continue to draw the attention of Russian people and people around the world to what's happening there," Naidoo said by telephone from the platform hours before evacuating. "It's bad for Russia, it's bad for the planet."

Gazprom is pioneering Russia's oil drilling in the Arctic. The state-owned company installed the platform there last year and is preparing to drill the first well.

The platform is about 1,000 kilometers from the nearest port, Murmansk, a city on the extreme northwestern edge of the Russian mainland.

Russian and international environmentalists have warned that drilling in the Russian Arctic could have disastrous consequences because of a lack of technology and infrastructure to deal with a possible spill in a remote region known for huge icebergs and severe storms.